Trenchers are conventionally used to dig lengths of trenches for laying underground pipe and cable. Most trenchers include a tractor unit equipped with an elongated boom. The boom is typically movable between a raised, generally horizontal position, and a lowered, substantially vertical position. The boom typically includes a cutting chain that is entrained about the boom. The chain generally includes exterior teeth or cutters for engaging the soil. Trenchers also commonly include a conveyer assembly for transporting the soil this is excavated by the chain.
There are various types of cutting teeth or attachments that are commonly bolted to a trencher digging chain. One of the most popular attachments is called a "cup tooth." An exemplary cup tooth cutter is disclosed in U.S. Pat. No. 3,022,588 to Brown. The '588 reference discloses a cup cutter having a leading edge and a cupped portion for scooping loose material from a trench. In use, essentially the entire leading edge of the cup cutter engages the wall of a trench.
Conventional cup tooth cutters, such as the cutter disclosed in the '588 patent, work effectively in easy digging conditions. However, in hard digging conditions, such cutters will generally wear out quickly. Consequently, conventional cup tooth cutters are not effective for excavating hard ground conditions.